The purpose of this program is to provide a daemonized version of the
spamassassin executable. The goal is improving throughput performance for
automated mail checking.

This is intended to be used alongside spamc, a fast, low-overhead C client
program.

See the README file in the spamd directory of the SpamAssassin distribution
for more details.

Note: Although spamd will check per-user config files for every message, any
changes to the system-wide config files will require either restarting spamd
or forcing it to reload itself via SIGHUP for the changes to take effect.

Note: If spamd receives a SIGHUP, it internally reloads itself, which
means that it will change its pid and might not restart at all if its
environment changed (ie. if it can't change back into its own directory). If
you plan to use SIGHUP, you should always start spamd with the -r
switch to know its current pid.

Options of the long form can be shortened as long as they remain
unambiguous. (i.e. --dae can be used instead of --daemonize)
Also, boolean options (like --user-config) can be negated by
adding no (--nouser-config), however, this is usually unnecessary.

Allow learning and forgetting (to a local Bayes database), reporting
and revoking (to a remote database) by spamd. The client issues a TELL
command to tell what type of message is being processed and whether
local (learn/forget) or remote (report/revoke) databases should be
updated.

Note that spamd always trusts the username passed in (unless
--auth-ident is used) so clients could maliciously learn messages
for other users. (This is not ususally a concern with an SQL Bayes
store as users will typically have read-write access directly to the
database, and can also use sa-learn with the -u option to
achieve the same result.)

Add additional lines of configuration directly from the command-line, parsed
after the configuration files are read. Multiple --cf arguments can be
used, and each will be considered a separate line of configuration.

Tells spamd to listen on the specified IP address (defaults to 127.0.0.1). If
you specify no IP address after the switch, spamd will listen on all interfaces.
(This is equal to the address 0.0.0.0). You can also use a valid hostname which
will make spamd listen on the first address that name resolves to.

Optionally specifies the port number for the server to listen on (default: 783).

If the --ssl switch is used, and --ssl-port is not supplied, then this
port will be used to accept SSL connections instead of unencrypted connections.
If the --ssl switch is used, and --ssl-port is set, then unencrypted
connections will be accepted on the --port at the same time as encrypted
connections are accepted at --ssl-port.

Turn on SQL lookups even when per-user config files have been disabled
with -x. this is useful for spamd hosts which don't have user's
home directories but do want to load user preferences from an SQL
database.

If your spamc client does not support sending the User: header,
like exiscan, then the SQL username used will always be nobody.

This inhibits the setuid() behavior, so the -u option is
required. If you want the setuid() behaviour, use -Q or
--setuid-with-sql instead.

Turn on SQL lookups even when per-user config files have been disabled
with -x and also setuid to the user. This is useful for spamd hosts
which want to load user preferences from an SQL database but also wish to
support the use of -H (Helper home directories.)

This option specifies where per-user preferences can be found for virtual
users, for the -x switch. The pattern is used as a base pattern for the
directory name. Any of the following escapes can be used:

So for example, if /vhome/users/%u/spamassassin is specified, and spamc
sends a virtual username of jm@example.com, the directory
/vhome/users/jm@example.com/spamassassin will be used.

The set of characters allowed in the virtual username for this path are
restricted to:

A-Z a-z 0-9 - + _ . , @ =

All others will be replaced by underscores (_).

This path must be a writable directory. It will be created if it does not
already exist. If a file called user_prefs exists in this directory (note:
not in a .spamassassin subdirectory!), it will be loaded as the user's
preferences. The Bayes databases for that user will be stored in this directory.

Note that this requires that -x is used, and cannot be combined with
SQL- or LDAP-based configuration.

The pattern must expand to an absolute directory when spamd is running
daemonized (-d).

Currently, use of this without -u is not supported. This inhibits setuid.

Write the process ID of the spamd parent to the file specified by pidfile.
The file will be unlinked when the parent exits. Note that when running
with the -u option, the file must be writable by that user.

Enable vpopmail config. If specified with with -u set to the vpopmail user,
this allows spamd to lookup/create user_prefs in the vpopmail user's own
maildir. This option is useful for vpopmail virtual users who do not have an
entry in the system /etc/passwd file.

Currently, use of this without -u is not supported. This inhibits setuid.

Specify the syslog facility to use (default: mail). If stderr is specified,
output will be written to stderr. (This is useful if you're running spamd
under the daemontools package.) With a facility of file, all output
goes to spamd.log. facility is interpreted as a file name to log to if it
contains any characters except a-z and 0-9. null disables logging completely
(used internally).

Examples:

spamd -s mail # use syslog, facility mail (default)

spamd -s ./mail # log to file ./mail

spamd -s stderr 2>/dev/null # log to stderr, throw messages away

spamd -s null # the same as above

spamd -s file # log to file ./spamd.log

spamd -s /var/log/spamd.log # log to file /var/log/spamd.log

If logging to a file is enabled and that log file is rotated, the spamd server
must be restarted with a SIGHUP. (If the log file is just truncated, this is
not needed but still recommended.)

Note that logging to a file does not use locking, so you cannot intermix
logging from spamd and other processes into the same file. If you want
to mix logging like this, use syslog instead.

If you use syslog logging, it is essential to send a SIGHUP to the spamd daemon
when you restart the syslogd daemon. (This is due to a shortcoming in Perl's
syslog handling, where the disappearance of the connection to the syslogd is
considered a fatal error.)

Specify how spamd should send messages to syslogd. The type can be any
of the socket types or logging mechanisms as accepted by the subroutine
Sys::Syslog::setlogsock(). Depending on a version of Sys::Syslog and on the
underlying operating system, one of the following values (or their subset) can
be used: native, eventlog, tcp, udp, inet, unix, stream,
pipe, or console. The value eventlog is specific to Win32 events
logger and requires a perl module Win32::EventLog to be installed.
For more information please consult the Sys::Syslog documentation.

A historical setting --syslog-socket=none is mapped to --syslog=stderr.

A default for Windows platforms is none, otherwise the default is
to try unix first, falling back to inet if perl detects errors
in its unix support.

Some platforms, or versions of perl, are shipped with old or dysfunctional
versions of the Sys::Syslog module which do not support some socket types,
so you may need to set this option explicitly. If you get error messages
regarding __PATH_LOG or similar spamd, try changing this setting.

The socket types file is used internally and should not be specified.
Use the -s switch instead.

The --log-timestamp-fmt option can provide a POSIX strftime(3) format for
timestamps included in each logged message. Each logger (stderr, file,
syslog) has its own default value for a timestamp format, which applies when
--log-timestamp-fmt option is not given, or with --log-timestamp-fmt=default .
Timestamps can be turned off by specifying an empty string with this
option, e.g. --log-timestamp-fmt='' or just --log-timestamp-fmt= .
Typical use: --log-timestamp-fmt='%a %b %e %H:%M:%S %Y' (provides
localized weekday and month names in the ctime(3) style),
or '%a, %e %b %Y %H:%M:%S %z (%Z)' for a RFC 2822 format,
or maybe '%Y-%m-%d %H:%M:%S%z' for an ISO 8601 (EN 28601) format,
or just '%Y%m%dT%H%M%S' .

Turn off (on) reading of per-user configuration files (user_prefs) from the
user's home directory. The default behaviour is to read per-user
configuration from the user's home directory (--user-config).

This option does not disable or otherwise influence the SQL, LDAP or
Virtual Config Dir settings.

Verify the username provided by spamc using ident. This is only
useful if connections are only allowed from trusted hosts (because an
identd that lies is trivial to create) and if spamc REALLY SHOULD be
running as the user it represents. Connections are terminated
immediately if authentication fails. In this case, spamc will pass
the mail through unchecked. Failure to connect to an ident server,
and response timeouts are considered authentication failures. This
requires that Net::Ident be installed.

Wait at most timeout seconds for a response to ident queries.
Authentication that takes long that timeout seconds will fail, and
mail will not be processed. Setting this to 0.0 or less results in no
timeout, which is STRONGLY discouraged. The default is 5 seconds.

Specify a list of authorized hosts or networks which can connect to this spamd
instance. Single IP addresses can be given, ranges of IP addresses in
address/masklength CIDR format, or ranges of IP addresses by listing 3 or less
octets with a trailing dot. Hostnames are not supported, only IP addresses.
This option can be specified multiple times, or can take a list of addresses
separated by commas. Examples:

-A 10.11.12.13 -- only allow connections from 10.11.12.13.

-A 10.11.12.13,10.11.12.14 -- only allow connections from 10.11.12.13 and
10.11.12.14.

-A 10.200.300.0/24 -- allow connections from any machine in the range
10.200.300.*.

Produce debugging output. If no areas are listed, all debugging information is
printed. Diagnostic output can also be enabled for each area individually;
area is the area of the code to instrument. For example, to produce
diagnostic output on bayes, learn, and dns, use:

spamassassin -D bayes,learn,dns

Higher priority informational messages that are suitable for logging in normal
circumstances are available with an area of "info".

For more information about which areas (also known as channels) are available,
please see the documentation at:

This option specifies the maximum number of children to spawn.
Spamd will spawn that number of children, then sleep in the background
until a child dies, wherein it will go and spawn a new child.

Incoming connections can still occur if all of the children are busy,
however those connections will be queued waiting for a free child.
The minimum value is 1, the default value is 5.

Please note that there is a OS specific maximum of connections that can be
queued (Try perl -MSocket -e'print SOMAXCONN' to find this maximum).

Note that if you run too many servers for the amount of free RAM available, you
run the danger of hurting performance by causing a high swap load as server
processes are swapped in and out continually.

The lower limit for the number of spare children allowed to run. A
spare, or idle, child is one that is not handling a scan request. If
there are too few spare children available, a new server will be started
every second or so. The default value is 1.

The upper limit for the number of spare children allowed to run. If there
are too many spare children, one will be killed every second or so until
the number of idle children is in the desired range. The default value
is 2.

By default, spamd will attempt to keep a small number of "hot" child
processes as busy as possible, and keep any others as idle as possible, using
something similar to the Apache httpd server scaling algorithm. This is
accomplished by the master process coordinating the activities of the children.
This switch will disable this scaling algorithm, and the behaviour seen in
the 3.0.x versions will be used instead, where all processes receive an
equal load and no scaling takes place.

This option specifies the number of seconds to wait for headers from a
client (spamc) before closing the connection. The minimum value is 1,
the default value is 30, and a value of 0 will disable socket
timeouts completely.

This option specifies the number of seconds to wait for a spamd child to
process or check a message. The minimum value is 1, the default
value is 300, and a value of 0 will disable child timeouts completely.

Specify that external programs such as Razor, DCC, and Pyzor should have
a HOME environment variable set to a specific directory. The default
is to use the HOME environment variable setting from the shell running
spamd. By specifying no argument, spamd will use the spamc caller's
home directory instead.

Accept only SSL connections on the associated port.
The IO::Socket::SSL perl module must be installed.

If the --ssl switch is used, and --ssl-port is not supplied, then
--port port will be used to accept SSL connections instead of unencrypted
connections. If the --ssl switch is used, and --ssl-port is set, then
unencrypted connections will be accepted on the --port, at the same time as
encrypted connections are accepted at --ssl-port.

Specify the SSL protocol version to use, one of
sslv2, sslv3, tlsv1, or sslv23.
The default, sslv23, is the most flexible, accepting a SSLv2 or higher
hello handshake, then negotiating use of SSLv3 or TLSv1 protocol if the client
can accept it.
Specifying --ssl-version implies --ssl.

Warning: the Perl support on BSD platforms for UNIX domain sockets seems to
have a bug regarding paths of over 100 bytes or so (SpamAssassin bug 4380). If
you see a 'could not find newly-created UNIX socket' error message, and the
path appears truncated, this may be the cause. Try using a shorter path
to the socket.

Set UNIX domain socket to be owned by the user named name. Note
that this requires that spamd be started as root, and if -u
is used, that user should have write permissions to unlink the file
later, for when the spamd server is killed.